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Updated: Aug 30, 2026
Using Deuterium Oxide as a Non-Invasive, Non-Lethal Tool for Assessing Body Composition and Water Consumption in Mammals
Published on: February 20, 2020
In Vivo Real-Time Metabolic Isotopic Tracing via Breath Analysis upon Deuterated Water Ingestion: A Proof-of-Concept
Zhihong Yin1,2, Kapil Dev Singh1,2, Zhifeng Tang3,4
1Department of Biomedical Engineering, University of Basel, Allschwil 4123, Switzerland.
Abstract:
Stable isotope tracing with deuterium oxide (D2O) offers a powerful approach for probing metabolic dynamics, yet noninvasive and real-time tools for monitoring in vivo deuterium (D) incorporation remain scarce. This study introduces secondary electrospray ionization-high-resolution mass spectrometry (SESI-HRMS) as a noninvasive, real-time approach for tracking D incorporation in human exhaled breath metabolites. A total of 11 healthy volunteers were enrolled across two independent study centers. Each participant provided up to 20 breath samples across fasting, post-D2O intake, and postprandial phases, yielding 213 samples in total. SESI-HRMS enabled the detection of 2,691 deuterium/hydrogen (D/H) pairs and revealed distinct metabolic trajectories associated with D labeling. Short-chain fatty acids (SCFAs) exhibited biphasic kinetics consistent with rapid orogastric exchange followed by microbial fermentation. Transient increases in pyruvaldehyde were associated with glycemic fluctuations, while dynamic alterations in medium-chain acylcarnitines suggested shifts in mitochondrial energy metabolism. Notably, SESI-HRMS unambiguously resolved D-labeled peaks from natural 13C isotopologues, demonstrating high analytical specificity for stable isotope tracing. Collectively, these findings demonstrate the feasibility of SESI-HRMS real-time breath analysis for noninvasive investigation of D-labeled metabolic dynamics in humans.
